Determination of Serum Vitamin-A, β-carotene, Total Proteins and Fractions in Women Within 24 Hours of Delivery from Different Age and Socioeconomic Groups

1997 ◽  
Vol 1 (1) ◽  
pp. 29-32 ◽  
Author(s):  
B. Tabassum ◽  
M. T. Javed . ◽  
N. Abbas . ◽  
Alia . ◽  
S. Pervaiz . ◽  
...  
2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 25-29 ◽  
Author(s):  
Guangwen Tang

Humans need vitamin A and obtain essential vitamin A by conversion of plant foods rich in provitamin A and/or absorption of preformed vitamin A from foods of animal origin. The determination of the vitamin A value of plant foods rich in provitamin A is important but has challenges. The aim of this paper is to review the progress over last 80 years following the discovery on the conversion of β-carotene to vitamin A and the various techniques including stable isotope technologies that have been developed to determine vitamin A values of plant provitamin A (mainly β-carotene). These include applications from using radioactive β-carotene and vitamin A, depletion-repletion with vitamin A and β-carotene, and measuring postprandial chylomicron fractions after feeding a β-carotene rich diet, to using stable isotopes as tracers to follow the absorption and conversion of plant food provitamin A carotenoids (mainly β-carotene) in humans. These approaches have greatly promoted our understanding of the absorption and conversion of β-carotene to vitamin A. Stable isotope labeled plant foods are useful for determining the overall bioavailability of provitamin A carotenoids from specific foods. Locally obtained plant foods can provide vitamin A and prevent deficiency of vitamin A, a remaining worldwide concern.


1956 ◽  
Vol 63 (3) ◽  
pp. 458-460 ◽  
Author(s):  
J. Gillman ◽  
K. Barbara Norton ◽  
D. E. A. Rivett ◽  
D. A. Sutton
Keyword(s):  

2008 ◽  
Vol 101 (6) ◽  
pp. 794-797 ◽  
Author(s):  
Pulin C. Sarma ◽  
Bhabesh C. Goswami ◽  
Krishna Gogoi ◽  
Harsha Bhattacharjee ◽  
Arun B. Barua

The objective of the present study was to determine marginal vitamin A deficiency (VAD) by testing the hydrolysis of retinoyl glucuronide (RAG) to retinoic acid (RA) in children. Previous studies in rats showed that hydrolysis occurred when rats were vitamin A deficient. Children (n 61) aged 3–18 years, were divided into two groups, I and II. Blood was collected from the children in Group I (n 19) who were not dosed with RAG. Children in Group II (n 42) were administered all-trans retinoyl glucuronide (RAG) orally, and blood was collected 4 h after the dose. All serum samples were analysed for retinoids and carotenoids. RA was detected in serum only when serum retinol was < 0·85 μmol/l. Thus, hydrolysis of RAG to RA occurred in children with VAD or marginal VAD. Serum retinol was < 0·35 μmol/l in twenty-one children, 0·35–0·7 μmol/l in twenty-three children, 0·7–0·9 μmol/l in eleven children and >1 μmol/l in six children. Mean serum retinol in sixty-one children was 0·522 (sd 0·315) μmol/l. Mean β-carotene (0·016 (sd 0·015) μmol/l) was far below normal compared to the level of lutein (0·176 (sd 0·10) μmol/l) in sixty-one children. A low β-carotene level might be due to a low intake of carotene but high demand for vitamin A. The RAG hydrolysis test may prove to be a useful approach for the determination of marginal VAD with no clinical or subclinical signs of VAD. High prevalence of VAD amongst certain communities in Assam cannot be ruled out.


2001 ◽  
Vol 84 (2) ◽  
pp. 354-360
Author(s):  
Vincenzo Pucci ◽  
Francesca Bugamelli ◽  
Roberto Mandrioli ◽  
Maria A Raggi

Abstract The concentrations of vitamin A, β-carotene, and all-trans-retinoic acid in oral preparations were determined in a single analysis by a method based on isocratic, reversed-phase liquid chromatography (LC). The LC system consisted of a C18 column, a mobile phase of acetonitrile, dichloromethane, methanol, and water and a UV detector set at 330 nm. The linearity ranges were 25–250 ng/mL for trans-retinoic acid and vitamin A, and 100–1000 ng/mL for β-carotene. This LC method for the determination of retinoids is simple, precise, and accurate. No extraction procedure is required before the chromatographic analysis; only a suitable dilution is necessary. The method proved to be reliable, fast, and economical. Furthermore, this method is indicative of stability, because it allows for the determination of degradation products such as 13-cis-retinoic acid.


1963 ◽  
Vol 41 (1) ◽  
pp. 543-549 ◽  
Author(s):  
J. Mathews ◽  
G. H. Beaton

Maintenance of rats on a protein-free, but not a 4% casein, diet produced a significant lowering of serum vitamin A. This effect was seen in rats deprived of vitamin A or provided with 90 μg of the vitamin twice weekly. In a separate study, rats maintained on 4% and 20% casein diets were depleted of vitamin A. They were then given 6 or 12 μg of vitamin A or 24 μg of carotene per day. The blood vitamin A response to administered vitamin A was not affected. Rats fed the low-protein diet exhibited only about one half of the serum vitamin A response to administered carotene as did those fed the 20% casein diet. Carotene failed to maintain liver vitamin A content in rats fed the low-protein diet. The results suggested that the absorption/conversion of β-carotene is impaired in rats maintained on a 4% protein diet. When rats were fed a protein-free diet the mobilization of vitamin A from the liver, or transport of the vitamin was also impaired.


1993 ◽  
Vol 20 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Gabriel A. Kune ◽  
Susan Kune ◽  
Barry Field ◽  
Lyndsey F. Watson ◽  
Heather Cleland ◽  
...  

2021 ◽  
pp. 36-44
Author(s):  
Rachel Nambafu ◽  
Sauda Swaleh ◽  
Hudson Nyambaka

Levels of vitamins in selected indigenous vegetables in Butula, western Kenya were determined and foods containing high levels of vitamin A and E were used to make food formulation. The bioavailability of these vitamins in food formulation was estimated using algorithm procedure. Determination of β-carotene and α-tocopherol content was done using HPLC procedure. Fresh blanched vegetables contained high levels of β-carotene; 4000 − 9700 µg/100g and α-tocopherol levels; 3000 − 7350 µg/100g. Solar dried vegetables contained β-carotene levels ranging from 572 − 854 µg/g and α-tocopherol levels ranging from 281 to 673 µg/g dry weights. Solar dried vegetables contained significantly lower (P<0.05) amounts of β-carotene and α-tocopherol as compared with fresh vegetables. The mean serum retinol α-tocopherol and β-carotene levels were 0.937, 0.144 and 17.787µmol/l respectively. Bioavailability estimated using algorithm indicated a +2.17 change in serum β-carotene and +7.776 changes in serum α-tocopherol, a positive indication that consumption of indigenous vegetables can meet the recommended dietary allowances of vitamins A (750 µg retinol equivalent/day) and E (8 mg/day). The bioavailable vitamins are capable of boosting the immune system and therefore delay early use of ARV’S.


1978 ◽  
Vol 61 (3) ◽  
pp. 753-755
Author(s):  
Teymour Kamangar ◽  
Ahmad B Fawzf

Abstract A spectrophotometric method for determining vitamin A based on interaction with 50% trichloroacetic acid solution in dichloromethane was developed. The blue reaction product had a maximum absorption at 620 nm and obeyed Beer's law over the concentration range of 0.5-5.0 μg retinol/ml solution. The molar absorptivity of the reaction product was 1.58 × 105. As much as 100 μg vitamin D2, and β-carotene up to 12 times the vitamin A concentration, did not interfere with the determination. The results obtained from the determination of vitamin A in cod liver oil and butter showed excellent agreement with the Carr-Price method, 43.013 (d).


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